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How can I have all outgoing mails with exim4 get signed by my dk-filter daemon running at localhost port 4445?

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You already asked this here, all-be-it somewhat buried in language about other options. Perhaps you should clean up your previous question with exactly what you want to accomplish. – Caleb Apr 16 '11 at 16:08
I'm hoping that someone has knowledge as to how I can have all outgoing emails piped through a local daemon on port 4445. I think that would do the trick. – ensnare Apr 16 '11 at 16:11
up vote 2 down vote accepted

Native domain keys support is available in Exim since version 4.70. See my notes on Implementing DKIM with Exim

If you want to use a filter you may want to review the Exim Documentation for filters. It includes instructions on how to test your filters.

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Add a new transport to your transport section. Connect your default outgoing mail router to use the new transport. Use the transport to pipe the mail through your daemon, then send it off to the original transport, whatever that was named (mine is remote_smtp).

   driver = pipe
   command = "/usr/bin/nc localhost 4445"
   transport = remote_smtp

Edit, better solution:

I just looked in the manual and it looks like you can add a transport_filter = "/usr/bin/nc localhost 4445" directive to an existing transport block to have messages filtered right before being sent by that transport.

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Thanks. I added this line to 30_exim4-config_remote_smtp but I get the error, " T=remote_smtp defer (-24): transport filter process failed (127): unable to execute command" – ensnare Apr 16 '11 at 17:13
Can you run that command manually? Your path might be different. Also the port might need to be marked with -p on your system. – Caleb Apr 16 '11 at 17:15
No more errors but for some reason all outgoing emails are now blank :-\ – ensnare Apr 16 '11 at 17:45

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